#include <stdio.h>
#include <string.h>
#include "item.h"
#include "stack.h"

int main(int argc, char *argv[]) 
{
  char *a = argv[1];
  int i, n = strlen(a);

  STACKinit(n);
  for (i = 0; i < n; i++)
    {
      if (a[i] == '+')
	STACKpush(STACKpop() + STACKpop());
      if (a[i] == '*')
	STACKpush(STACKpop() * STACKpop());
      if ((a[i] >= '0') && (a[i] <= '9'))
	STACKpush(0);
      while ((a[i] >= '0') && (a[i] <= '9'))
	STACKpush(10 * STACKpop() + (a[i++] - '0'));
    }
  printf("%d \n", STACKpop());
  return 0;
}
